This invention relates to power distribution panelboards that are particularly well suited for field assembly. It further relates to such panelboards which accept plug-in enclosed fusible switches and plug-in molded case circuit breakers in the same panelboard, and which further accept plug-in enclosed lug main units.
Panelboards are known which accept plug-in molded case circuit breakers of varying sizes and ratings, or which accept both enclosed fusible switches and circuit breakers when the circuit breaker is provided within a metallic box enclosure similar to the enclosure of the fusible switch. It is also known to provide panelboards which may be distributor stocked as separate parts and, to a limited extent, field assembled to one of several predetermined arrangements of circuit breakers and/or enclosed fusible switches. While the known panelboards have generally been satisfactory for their intended purposes, they have required distributors to maintain a large inventory of individual parts including factory assembled panels and main power feed devices. Additionally, versatility in the arrangement of circuit breakers and/or enclosed fusible switches has been limited.